Greensboro, North Carolina (CNN) - John Edwards' defense team hammered away at a former campaign aide on Thursday after he was quizzed about his motives and asked whether he made up stories about how Edwards allegedly concealed contributions from campaign donors.

On day four of the trial, Andrew Young, the former aide, said "we lost our perspective" during cross examinations, acknowledging using donations for personal expenses at a California home. Young, testifying in U.S. District Court in Greensboro, North Carolina, said he used the funds in constructing a pool and a theater.

Greensboro, North Carolina (CNN) - A former campaign aide of John Edwards will face more questions Thursday, a day after he was quizzed about his motives and asked whether he made up stories about how Edwards allegedly concealed contributions from campaign donors.

Andrew Young, the former aide, testified Wednesday on day three of the trial at U.S. District Court in Greensboro, North Carolina. He is considered the government's star witness against Edwards, who is accused of using hundreds of thousands of dollars of donations to conceal his affair with a campaign videographer without reporting the money to federal authorities.

Greensboro, North Carolina (CNN) –A former campaign aide of John Edwards faced questions Wednesday about his motives for testifying against the former presidential candidate and whether he made up stories about how Edwards allegedly concealed contributions from campaign donors.

Andrew Young, the former aide, was testifying on day three of the trial at U.S. District Court in Greensboro, North Carolina. He is considered the government's star witness against Edwards, who is accused of using hundreds of thousands of dollars of donations to conceal his affair with a campaign videographer without reporting the money to federal authorities.